ORNL has three mechanisms established or under development for surface treatment of carbon fiber: 1) electrochemical, the most common industrial surface treatment method (exists at the Carbon Fiber Technology Facility, or CFTF); 2) thermochemical, a new technique developed at ORNL for oxidative surface treatment of carbon fiber; and 3) plasma-based surface treatment, a highly flexible and effective technique at atmospheric pressure that can impart a variety of chemical functionalities on carbon fiber surfaces.
At the CFTF, electrochemical surface treatment can accommodate 24 tows of up to 24,000 filaments. Thermochemical surface treatment is at RMX Technologies and can accommodate three tows. Plasma surface treatment also is at RMX Technologies and can accommodate three tows.
Electrochemical surface treatment is aqueous-based and requires multiple steps of washing and drying to achieve the desired properties. CFTF can achieve around 8% atomic oxygen content on the filament surface (via x-ray photoelectron spectroscopy [XPS] analysis). Thermochemical surface treatment is a gas phase system that, when properly applied, has very high efficiency and is easy to manage (only for oxidative treatment). Plasma surface treatment is a gas phase, atmospheric pressure, glow (non-filamentary) discharge system that can impart a variety of chemical functionalities on carbon fiber filaments uniformly over large surfaces without pitting/ablating the filaments.
The ORNL Precursor Evaluation System has one lab-scale thermochemical surface treatment device located at RMX Technologies. RMX Technologies also houses the plasma surface treatment equipment. All are available for evaluation.
Dr. Felix Paulauskas, Senior Carbon Fiber Researcher, email@example.com, 865-576-3785